The clothes fit because it’s the same bodies. 🙂 Though we see Gary in Sam’s clothes, when Dean is looking at Sam (with Gary inhabiting his body), Dean sees Sam in Sam’s clothes. 🙂
Those mirror scenes WERE really good!
I thought Sam did indicate that something was sore when he was back in his body? Maybe I’m thinking of him rubbing his butt after Changing Channels when he “was” the Impala and Dean was rummaging around in the trunk.